Bone repair composition and kit

ABSTRACT

A biocompatible material for bone repair is described. The bone repair composition includes a mixture of a type I collagen, a type I collagen-glycosaminoglycan coprecipitate, tricalcium phosphate; and bioactive glass. Methods of using the composition for bone repair, and a kit for the bone repair composition are also described.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. Ser.No. 16/230,399 (the entire contents of which are incorporated herein byreference).

BACKGROUND

The repair of bone defects can be facilitated by placing a bone repairmaterial as a temporary substitute at the site of the bone defect. Onceplaced, the bone repair material promotes and guides the regeneration ofa natural bone structure.

Both naturally-derived and synthetically-produced bone repair materialscan be used to repair bone defects. Naturally-derived materials includegrafts made from bone. The bone may be harvested directly from thepatient, as in autograft-based procedures, or it may be harvested from asuitable donor, surrogate, or cadaver, as in allograft- orxenograft-based procedures. However, autograft bone implant proceduresare costly and cause additional discomfort for the patients, as theytypically require an additional surgery for harvesting the graftmaterial, which may cause significant morbidity at the donor site.Autografts may also show pronounced resorption making the outcome of therepair unpredictable.

Allogenic bone repair materials can also be used for bone repair, buttheir origin raises possible pathogenic transfers and ethical issues.Similar concerns are brought up against xenogenic graft materials.Alternatively, naturally-derived bone repair materials may be replacedby a completely synthetic bone repair material. Unfortunately, incontrast to naturally-occurring bone repair materials, synthetic bonerepair materials are often less osteoconductive and are poorlyosteoinductive.

While significant research has been carried out in the area of bonerepair materials, there remains a need for improved bone repairmaterials that are biocompatible, durable, and effectively stimulatebone repair.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a bone repair composition.The composition includes a mixture of: a type I collagen; a type Icollagen-glycosaminoglycan coprecipitate; tricalcium phosphate; andbioactive glass. In some embodiments, the tricalcium phosphate comprisesparticles having a size from 500 to 1400 microns. In some embodiments,the bioactive glass comprises particles having a size from 500 to 1000microns. In some embodiments the bioactive glass comprises from 15% to25% by weight, while in additional embodiments the tricalcium phosphatecomprises from 75% to 85% by weight. In additional embodiments, thebioactive glass develops a hydroxyapatite surface layer uponimplantation within a subject. In some embodiments, the bone repaircomposition exhibits a color change upon sterilization. In an additionalembodiment, the bone repair composition is configured as a rectangularstrip.

In additional embodiments of the bone repair composition, theglycosaminoglycan can be chondroitin 4 sulfate or chondroitin 6 sulfate.In some embodiments, the combined weight percent of the type I collagenand the type I collagen-glycosaminoglycan coprecipitate is from 1% to5%. In further embodiments, the type I collagen-glycosaminoglycancoprecipitate comprises a ratio of glycosaminoglycan to type I collagenfrom between 1 to 10 and 1 to 12. In some embodiments the type Icollagen in a ratio of about 1:1 compared with type Icollagen-glycosaminoglycan coprecipitate. In additional embodiments, thetype I collagen comprises fine flakes or particles obtained by millingcollagen through a 20 mesh screen.

Another aspect of the invention provides a method of repairing a bonedefect, comprising administering a bone repair composition as describedherein to the site of the defect. For example, in some embodiments thecomposition is configured as a rectangular strip. In some embodiments,the composition is hydrated with autologous blood before administeringthe composition to the site of the defect. In some embodiments, the bonedefect is, or is the result, a simple fracture, a compound fracture,external fixation, internal fixation, joint reconstruction,arthroplasty, degenerative disc disease, avascular osteonecrosis,osteosarcoma fracture, fracture non-unions, spinal fusion, discaugmentation, or bone regeneration in orthopedic implants.

Another aspect of the invention provides a bone repair kit. The bonerepair kit includes a bone repair composition, comprising a mixture of:a type I collagen; a type I collagen-glycosaminoglycan coprecipitate;tricalcium phosphate; and bioactive glass; and a package for holding thebone repair composition. In some embodiments, the bone repaircomposition is configured as a rectangular strip. In some embodiments,the kit further comprising instructions for repairing a bone defect. Infurther embodiments, the packaging includes a tray configured to fit theshape of the bone repair composition. In yet further embodiments, thetray includes one or more grip regions to facilitate access to the bonerepair composition. In some embodiments, the package comprises highdensity polyethylene.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 provides a perspective view of a rectangular strip of the bonerepair composition.

FIGS. 2A-2D provide drawings showing (A) a perspective view of the bonerepair tray; (B) a top view of the bone repair tray; (C) a side view ofthe bone repair tray; and (D) a sectional view of the bone repair tray.

FIGS. 3A-3D provide drawings showing (A) a perspective view of the bonerepair kit cover; (B) a top view of the bone repair kit cover; (C) aside view of the bone repair kit cover; and (D) a sectional view of thebone repair kit cover.

FIG. 4 provides a scheme showing the process flow for collagen strippreparation.

FIG. 5 provides a scheme showing the process flow outlining 1000 mlCollagen-co-GAG production through collagen strip dispersion.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a biocompatible material for bone repair.The bone repair composition includes a mixture of a type I collagen, atype I collagen-glycosaminoglycan coprecipitate, tricalcium phosphate;and bioactive glass. Methods of using the composition for bone repair,and a kit for packaging the bone repair composition are also described.

The terminology as set forth herein is for description of theembodiments only and should not be construed as limiting of theinvention as a whole. Unless otherwise specified, “a,” “an,” “the,” and“at least one” are used interchangeably. Furthermore, as used in thedescription of the invention and the appended claims, the singular forms“a”, “an”, and “the” are inclusive of their plural forms, unlesscontraindicated by the context surrounding such.

Also herein, the recitations of numerical ranges by endpoints includeall numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2,2.75, 3, 3.80, 4, 5, etc.).

As used herein, the term “about,” when referring to a value or to anamount of mass, weight, time, volume, concentration or percentage ismeant to encompass variations of in some embodiments ±20%, in someembodiments ±10%, in some embodiments ±5%, in some embodiments ±1%, insome embodiments ±0.5%, and in some embodiments ±0.1% from the specifiedamount, as such variations are appropriate to perform the disclosedmethod.

The terms “comprises,” “comprising,” “includes,” “including,” “having”and their conjugates mean “including but not limited to”. This termencompasses the terms “consisting of” and “consisting essentially of”.

The phrase “consisting essentially of” means that the composition ormethod may include additional ingredients and/or steps, but only if theadditional ingredients and/or steps do not materially alter the basicand novel characteristics of the claimed composition or method.

A “subject,” as used herein, can be any animal, and may also be referredto as the patient. Preferably the subject is a vertebrate animal, andmore preferably the subject is a mammal, such as a research animal(e.g., a mouse or rat) or a domesticated farm animal (e.g., cow, horse,pig) or pet (e.g., dog, cat). In some embodiments, the subject is ahuman.

The terms “therapeutically effective” and “pharmacologically effective”are intended to qualify the amount of each agent which will achieve thegoal of decreasing disease severity while avoiding adverse side effectssuch as those typically associated with alternative therapies. Thetherapeutically effective amount may be administered in one or moredoses.

“Biocompatible” as used herein, refers to any material that does notcause injury or death to a subject or induce an adverse reaction in asubject when placed in contact with the subject's tissues. Adversereactions include for example inflammation, infection, fibrotic tissueformation, cell death, or thrombosis. The terms “biocompatible” and“biocompatibility” when used herein are art-recognized and mean that thematerial is neither itself toxic to a subject, nor degrades (if itdegrades) at a rate that produces byproducts at toxic concentrations,does not cause prolonged inflammation or irritation, or does not inducemore than a basal immune reaction in the host.

As used herein, “treatment” means any manner in which the symptoms of adefect, condition, disorder, or disease, or any other indication, areameliorated or otherwise beneficially altered.

Bone and Bone Repair

Long bones are composed of a dense outer cortical bone (also calledcompact bone), which encloses an irregular medullary space or cavitycontaining cancellous bone. The cortical bone is a dense and compactbone that generally has a higher mineral content than cancellous boneand higher stiffness and strength. The primary structural unit of thecortical bone is the osteon or haversian system, which is made up ofcylindrical shaped lamellar bone that surrounds vascular channels calledhaversian canals. The outer cortical surface is enveloped in theperiosteum, which is a connective tissue that contains blood vessels,sensory nerves and dense fibrous tissue and cells that maintain, changeand repair the external cortical surface. The cancellous bone (alsocalled spongy bone or trabecular bone) is composed of a branchingnetwork of interconnecting bony trabecular elements and contains cellsthat have osteogenic potential. Osteoprogenitor cells are present in theendosteum that lines the inner surface of the bone and covers thetrabeculae of the cancellous bone, and also in the periosteum.

In response to injury, bone is able to regenerate and remodel to healitself. For example, uncomplicated fractures are able to heal withoutsurgical intervention in 6 months or less. The process of healingincludes endochrondral or intramembranous ossification. In general, inresponse to injury, mesenchymal stem cells from the surrounding tissuemigrate into the wound site and differentiate into cartilage or bonecells (i.e. osteoblasts). A typical sequence of events includes:hemorrhage; clot formation; dissolution of the clot with concurrentremoval of damaged tissues; ingrowth of granulation tissue; formation ofcartilage; capillary ingrowth and cartilage turnover; rapid boneformation (bony callus); and, finally, remodeling of the callus intocortical and trabecular bone. Bone repair, therefore, is a complexprocess that involves many cell types and regulatory molecules. Thediverse cell populations involved in fracture repair include stem cells,macrophages, fibroblasts, vascular cells, osteoblasts, chondroblasts,and osteoclasts.

Bone Repair Compositions

One aspect of the present invention provides a bone repair composition.The bone repair composition includes a mixture of a type I collagen; atype I collagen glycosaminoglycan coprecipitate; tricalcium phosphate;and bioactive glass. A “composition,” as used herein, refers to anymixture of materials. It can be a solid, suspension, powder,particulate, paste, or any combination thereof. In some embodiments, thecomposition is a solid particulate dispersion.

Collagen is the major protein component of bone, cartilage, skin, andconnective tissue in animals. Collagen occurs in several types, havingdiffering physical properties. The most abundant types are Types I, IIand III. Collagen derived from any source is suitable for use in thecompositions of the present invention, including insoluble collagen,collagen soluble in acid, in neutral or basic aqueous solutions, as wellas those collagens that are commercially available. Typical animalsources for collagen include but are not limited to recombinantcollagen, fibrillar collagen from bovine, porcine, ovine, caprine,avian, and shark sources as well as soluble collagen from sources suchas cattle bones and rat tail tendon. In some embodiments, the collagenis obtained from corium, which is a base material from which collagen isextracted.

Type I collagen is the most abundant collagen of the human body whichforms large, eosinophilic fibers known as collagen fibers. The COL1A1gene produces the pro-alpha1 (I) chain. This chain combines with anotherpro-alpha1(I) chain and also with a pro-alpha2(I) chain (produced by theCOL1A2 gene) to make a molecule of type I procollagen. Type I collagenis present in scar tissue, as well as tendons, ligaments, the endomysiumof myofibrils, the organic part of bone, the dermis, the dentin andorgan capsules.

The collagen included in the bone repair composition can be in the formof small flakes, particles, or fibers. Small flakes or particles can beobtained by milling a collagen sponge, or other form of collagen havinga reticulated cellular structure. For example, in some embodiments, thecollagen comprises fine flakes or particles obtained by milling collagenthrough a 10, 20, or 30 mesh screen. A preferred size is obtained bymilling collagen through a 20 mesh screen.

The collagen is included in the bone repair composition both as type Icollagen and as a type I collagen-glycosaminoglycan coprecipitate. Insome embodiments, the ratio of type I collagen to type Icollagen-glycosaminoglycan coprecipitate ranges from about 0.5:1 toabout 2:1. In further embodiments, the ratio of type I collagen to typeI collagen-glycosaminoglycan coprecipitate ranges from about 0.8:1 toabout 1.5:1. In further embodiments, the type I collagen is present in aratio of about 1:1 compared with type I collagen glycosaminoglycancoprecipitate.

The amount of type I collagen included in the bone repair compositioncan vary from about 0.5% to about 20% by weight. In some embodiments,the bone repair composition includes from 0.5% to 15% collagen byweight, in further embodiments, the bone repair composition includesfrom 0.5% to 10% collagen by weight, in yet further embodiments, thecombined weight percent of the type I collagen and the type Icollagen-glycosaminoglycan coprecipitate is from 1% to 5%, while inadditional embodiments the bone repair composition includes an amountfrom 2% to 4% type I collagen, from the pure and co-precipitate forms ofcollagen, combined.

The bone repair composition also includes a type Icollagen-glycosaminoglycan coprecipitate. The type Icollagen-glycosaminoglycan coprecipitate is formed when collagen isprecipitated from acid dispersion by addition of a GAG such aschondroitin 6-sulfate. The relative amount of GAG in the coprecipitatevaries with the amount of GAG added and with the pH. Yannas et al., JBiomed Mater Res., 14(2):107-32 (1980). The coprecipitate ispredominantly collagen. In some embodiments, the type I collagenglycosaminoglycan coprecipitate comprises a ratio of glycosaminoglycanto type I collagen from between 1 to 8 and 1 to 15. In furtherembodiments, the type I collagen glycosaminoglycan coprecipitatecomprises a ratio of glycosaminoglycan to type I collagen from between 1to 10 and 1 to 12. In some embodiments, the ratio is about 1 to 11.

The term glycosaminoglycan (GAG) describes hexosamine-containingpolysaccharides. Glycosaminoglycans are also referred to asmucopolysaccharides. Chemically, GAG are alternating copolymers made upof residues of hexosamine that are glycosidically bound and alternatingin a more or less regular manner with either hexuronic acid or hexosemoieties. Glycosaminoglylcans can be obtained from various marine andmammalian sources.

Examples of glycosaminoglycan molecules that can be included in the bonerepair composition include hyaluronic acid and chondroitin sulfate.Various forms of GAG which may be suitable for use in the bone repaircomposition include, but are not limited to, hyaluronic acid,chondroitin 6-sulfate, chondroitin 4-sulfate, heparin, heparin sulfate,keratin sulfate and dermatan sulfate. In some embodiments, theglycosaminoglycan included in the bone repair composition is chondroitin4 sulfate or chondroitin 6 sulfate.

The bone repair composition also includes a bone growth stimulator(e.g., tricalcium phosphate). Typically, this is the main materialincluded in the bone repair composition, by weight. In some embodiments,the bone growth stimulator (e.g., tricalcium phosphate) comprises from60% to 95% by weight, from 65% to 90% by weight, from 70% to 90% byweight, from 75% to 85% by weight, or from 75% to 80% by weight.

Suitable bone growth stimulators include substances that can enhancebone repair. Some examples of bone growth stimulators include, but arenot limited to, calcium, hydroxyapatite, tricalcium phosphate, chitosan,coral derivatives, bone growth factors, such as for example bonemorphogenic proteins, and the like. Hydroxyapatite includesCa₁₀(PO₄)₆(OH)₂, and is exogenous calcium phosphate that resembles theprimary inorganic component of bone. This agent provides an osteophillicmatrix for bone to bond and grow. A preferred bone growth stimulator forinclusion in the bone repair composition is tricalcium phosphate(Ca₃(PO₄)₂). This term also includes sources or variants of tricalciumphosphate, such as bone ash, alpha or beta tricalcium phosphate, andcombinations thereof.

The bone growth stimulator (e.g., tricalcium phosphate) is included inthe bone repair composition as small particles. In some embodiments, theparticles have a size from 250 to 2500 microns. In other embodiments,the particles have a size from 300 to 2000 microns. In furtherembodiments, the particles have a size from 400 to 1600 microns. In yetfurther embodiments, the particles have a size from 500 to 1400 microns.In additional embodiments, the particles have a size from 600 to 1200microns.

The bone repair composition also includes bioactive glass. Bioactiveglass is glass that is glass that undergoes specific surface reactionswhen implanted into a subject that facilitates integration andbiocompatibility of the material. For example, in some embodiments thebioactive glass develops a hydroxyapatite surface layer uponimplantation that facilitates the formation of a firm bond with hard andsoft tissues. Bioactive glass is commercially available from companiessuch as Prosidyan® and the Mo-Sci Corporation. Bioactive glass is basedon Silicon Dioxide (SiO₂) but also typically includes lesser amounts ofCalcium Oxide (CaO), Sodium Oxide (Na₂O), and Phosphorus Pentoxide(P₂O₅). Embodiments of the bone repair composition can include varyingamounts of the bioactive glass. In some embodiments, the bone repaircomposition includes from 10% to 98% bioactive glass by weight. In otherembodiments, the bone repair composition can include 5% to 40% bioactiveglass by weight. In other embodiments, the composition includes from 10%to 30% bioactive glass. In other embodiments, the composition includesfrom 15% to 25% bioactive glass, while in further embodiments, thecomposition includes from 18% to 23% bioactive glass. High levels ofbioactive glass can be obtained by replacing ceramic material withbioactive glass.

The bioactive glass is included in the bone repair composition as smallparticles. In some embodiments, the bioactive glass particles have asize from 100 to 2000 microns. In other embodiments, the bioactive glassparticles have a size from 250 to 1500 microns. In further embodiments,the bioactive glass particles having a size from 500 to 1000 microns.

The various materials included in the bone repair composition can becross-linked to increase the stability of materials prepared using thebone repair composition. Collagen can be crosslinked using methodsgenerally known in the art, such as by heat, radiation, or usingconventional chemical crosslinking agents such as, for example,aldehydes, carbodiimides, epoxides, or imidazoles. One suitable chemicalmethod for covalently cross-linking collagen/GAG matrices is known asaldehyde cross-linking. In this process, the materials are contactedwith aqueous solutions of aldehyde, which serve to cross-link thematerials. Suitable aldehydes include formaldehyde, glutaraldehyde andglyoxal. The preferred aldehyde is glutaraldehyde because it yields adesired level of cross-link density more rapidly than other aldehydesand is also capable of increasing the cross-link density to a relativelyhigh level. When glutaraldehyde is used as the cross-linking agent, itis preferred that nontoxic concentrations of greater than about 0.25% beused. Other chemical techniques that are suitable for increasingcross-link density in the present invention include carbodiimidecoupling, azide coupling, and diisocyanate cross-linking.

The bone repair composition can further comprise bioactive molecules tofacilitate bone repair or have other beneficial effects. Suitablebioactive molecules include, but are not limited to, growth factors,anti-inflammatory agents, wound healing agents, anti-scarring agents,antimicrobial agents (for example, silver), cell-adhesion peptidesincluding Arg-Gly-Asp (RGD) containing peptides, nucleic acids, nucleicacid analogues, proteins, peptides, amino acids, and the like, orcombinations thereof.

Pharmacologically active agents that can be included in the bone repairincludes, for example, VEGF (vascular endothelial cell growth factor),FGF (the fibroblast growth factor family of proteins), TGFβ(transforming growth factor B), hepatocyte growth factor (HGF), plateletfactor 4 (PF4), PDGF (platelet derived growth factor), EGF (epidermalgrowth factor), NGF (nerve growth factor), BMP (bone morphogeneticprotein family), coagulation factors such as one of the vitaminK-dependent coagulant factors, such as Factor II/IIa, Factor VIINIIa,Factor IX/IXa or Factor X/Xa. Factor V/Va, VIIINIIIa, Factor XI/XIa,Factor XII/XIIa, Factor XIII/XIIIa, and mixtures thereof may also beused. Antibiotics, antifungal agents, hormones, enzymes, enzymeinhibitors, and mixtures thereof can also be incorporated in thecompositions of the instant invention and subsequently delivered to thewound site.

The bone repair composition can be treated to sterilize or to reducebioburden of the material. For example, sterilization procedures caninclude low dose irradiation, antibiotic washing and physicaldebridement. These methods provide the benefit of reducing antigenicityas well as sterilizing the bone repair composition. More extensivesterilization can be provided through gamma irradiation, electron beamirradiation, or ethylene oxide treatment.

In some embodiments, the bone repair composition exhibits a color changeupon sterilization. For example, the bone repair composition, which istypically white or off-white in color, can darken to a gray or blackupon exposure to irradiation (e.g., gamma irradiation). Thisdemonstrates that sterilization has been effective, and can alsoindicate if the bone repair composition has subsequently beencontaminated, which can shift the color back to white or off-white. Thistype of color change is mediated by the bioactive glass included in thebone repair composition.

The bone repair composition provides a biocompatible material that canbe implanted at the site of a bone defect to facilitate bone repair. Theshape and dimensions of the material can vary depending on the type ofbone defect that is being repaired. For example, the bone repaircomposition can be configured as a sheet, a rod, a sphere, a tube, acone, or a rectangular strip. FIG. 1 provides a perspective view of arectangular bone repair composition strip 10, having a rectangular topsurface 12 and sides 14. Furthermore, the shape of the bone repaircomposition can be modified immediately before use by cutting ortrimming the bone repair material. In one embodiment, these dimensionsmay range from about 1 cm to about 1 meter in length, for example, fromabout 3 cm to about 8 cm in length, from about 0.5 mm to about 30 mm inthickness, for example, from about 2 mm to about 10 mm in thickness, andfrom about 0.05 mm to about 150 mm in width, for example, from about 2mm to about 10 mm in width.

Methods of Bone Repair

In one aspect, the present invention provides a method of repairing abone defect, comprising administering a bone repair composition to thesite of the defect. The bone repair composition can be any of the bonerepair compositions described herein.

The bone repair composition can be used to promote bone growth and/orbone remodeling, including in the treatment of any of a variety of bonediseases, disorders, defects or injuries for which other bone grafts,including allografts or autografts, have been employed. Such diseases,disorders, defects or injuries are well known to a skilled artisan. Thesubject for treatment can be any animal subject that has a bone disease,disorder, defect or injury and is in need of treatment, including anymammal, such as a human or non-human primate. In particular examples,the subject is a human. The bone repair composition can be used to fillor partially fill bone voids and/or gaps of the skeletal systemassociated with the bone disease, disorder, defect or injury.

For example, the bone repair compositions described herein can be usedto correct bone defects in orthopedic, neurosurgical plastic orreconstructive surgery, in periodontal procedures, and in endodonticprocedures. Such applications include, but are not limited to, inductionof bone formation for hip replacement operations, knee replacementoperations, foot and ankle surgeries (e.g. ankle fusion), spinal fusionprocedures, repair of periodontal defects, treatment of osteoporosis,repair of bone tumor defects, dental procedures, repair of cranialmaxilla facial defects and repair of bone fractures or defects. The bonedisease, disorder, defect or injury can result from a developmentalfailure, or by degeneration or trauma, caused naturally or by surgery.Preferably the bone defect being repaired is not a load-bearing bone.

Non-limiting examples include repair of simple and compound fracturesand non-unions, external and internal fixations, joint reconstructionssuch as arthrodesis, general arthroplasty, cup arthroplasty of the hip,femoral and humeral head replacement, femoral head surface replacementand total joint replacement, repairs of the vertebral column includingspinal fusion and internal fixation, tumor surgery, e.g. deficitfilling, discectomy, laminectomy, excision of spinal cord tumors,anterial cervical and thoracic operations, repair of spinal injuries,scoliosis, lordosis and kyphosis treatment, intermaxillary fixation offractures, mentoplasty, temporomandibular joint replacement, alveolarridge augmentation and reconstruction, inlay bone grafts, implantplacement and revision or sinus lifts.

For example, bone diseases, disorders, defects, or injuries that can betreated with bone repair compositions provided herein include, but arenot limited to, bone detects that include or are the result of a simplefracture, a compound fracture, external fixation, internal fixation,joint reconstruction, arthroplasty, degenerative disc disease, avascularosteonecrosis, osteosarcoma fracture, fracture non-unions, spinalfusion, disc augmentation, or bone regeneration in orthopedic implants.

The bone repair composition can be administered directly to the site ofthe bone disease, disorder, defect, or injury. In particular, the bonerepair composition can be packed directly onto the site affected by thebone disease, disorder, defect, or injury. For example, the bone repaircomposition can be packed into bony voids. In some embodiments, the bonerepair composition can be molded or formed into a desired shapegenerally conforming to the shape and size of the defect site, and thenpositioned or pressed, either manually and/or using instrumentation,into the defect site. For example, in some embodiments, the bone repaircomposition is configured as a rectangular strip. If necessary, a covercan be applied over the product where it has been applied or packed intobone.

In some embodiments, the bone repair composition is hydrated with aphysiological solution before administering the bone repair compositionto the defect. A physiological solution is one that contains a saltcomposition and osmotic pressure similar to blood plasma. In someembodiments, the physiological solution is autologous blood. There areseveral advantages associated with the use of autologous blood tohydrate the bone repair composition. First, it will be readily availableduring a bone repair procedure without requiring additional steps, andsince it is fresh and from the subject undergoing bone repair it willnot cause rejection, and will not require the use of stabilizers oranticoagulants. Second, autologous blood also provides useful bloodcomponents such as stem cells and growth factors in the appropriatephysiological amounts, which can simulate and support the naturalcascade of events involved in bone repair. Finally, the use ofautologous blood will minimize the risk of infection during surgery.

In some examples, the bone repair composition can be used in conjunctionwith devices employed in the treatment of bone diseases, defects,disorders and injuries, such as, for example, orthopedic cage devices,ceramics or plates that can be employed in the spine or in bones topromote bone growth and fusion. Furthermore, the bone repair compositioncan be used in conjunction with an autologous bone graft. The bonerepair composition also can be administered with antibiotic,antimycotic, or other anti-inflammatory agents. In some cases, the bonerepair composition can be administered in combination withosteoinductive factors, such as BMP-2, BMP-7, and/or PDGF, or thepatient's blood, platelet rich plasma (PRP) or bone marrow in order toenhance bone repair.

Bone Repair Kits

Another aspect of the invention provides a bone repair kit. The kitincludes a bone repair composition, comprising a mixture of: a type Icollagen; a type I collagen glycosaminoglycan coprecipitate; tricalciumphosphate; and bioactive glass; and a package for holding the bonerepair composition.

In addition to the above components, the subject kits may furtherinclude (in certain embodiments) instructions for repairing a bonedefect using the bone repair composition. These instructions may bepresent in the subject kits in a variety of forms, one or more of whichmay be present in the kit. One form in which these instructions may bepresent is as printed information on a suitable medium or substrate,e.g., a piece or pieces of paper on which the information is printed, inthe packaging of the kit, in a package insert, etc. Yet another form ofthese instructions is a computer readable medium, e.g., diskette,compact disk (CD), hard drive etc., on which the information has beenrecorded. Yet another form of these instructions that may be present isa website address which may be used via the internet to access theinformation at a removed site.

Use of the kit described herein provides a number of advantages. The kitfacilitates maintaining sterility and integrity of the bone repairmaterial. In some embodiments, the kit includes an inner tray thatsupports the bone repair material while providing improved access toforceps or fingers for removing the bone repair material from the kit.The inner tray is preferably configured to provide a chair configurationto support the bone repair material. This facilitates hydration of thebone repair material using, for example autologous blood by providing aregion where the bone repair material can be allowed to drain afterhaving been soaked in a hydrating solution. Hydrating the bone repairmaterial in autologous blood using an inner tray including a chairregion helps avoid puddling or blockage of the blood, while encouragingequal distribution of the blood through the bone repair material. Insome embodiments, the kit also includes an outer tray that helps deliverthe inner tray and the bone repair material to the sterile surgeryfield.

As used herein, the term “package” refers to a solid matrix or materialsuch as glass, plastic, paper, foil and the like capable of holding thebone repair composition. For example, in some embodiments, the packagecomprises high density polyethylene. Preferable the package istransparent in order to allow the bone repair composition to be viewedfrom outside the package. In some embodiments, the package includes atray that includes one or more grip regions to facilitate access to thebone repair composition.

The kits may also comprise one or more container means for containing asterile, pharmaceutically acceptable fluid or optional components. Insome embodiments, the kit includes distinct container means for eachcomponent. In such cases, one container could contain, for example, thecollagen particles, and the other container could include, for example,the physiologically acceptable fluid. The kit can also include asolution to formulate the matrix component, both components separately,or a pre-mixed combination of the components, into a more gelatinousform for application to the body. It should be noted, however, thatcomponents of a kit could be supplied in a dry form, which would allowfor “wetting” upon contact with body fluids (e.g., autologous blood).Thus, the presence of any type of physiologically acceptable fluid isnot a requirement for the kits of the invention.

In some embodiments, the packaging includes a tray configured to fit theshape of the bone repair composition. FIGS. 2A-2D provide drawingsshowing an example of a bone repair tray 20 configured fit the shape ofa bone repair composition 10 provided as a rectangular strip, as shownin FIG. 1. The bone repair tray 20 includes a flat tray sealing region22 that provides a surface that can be associated with or bonded to aflat sheet (e.g., a paper sheet, not shown) to seal the bone repair tray20. The version of the bone repair tray 20 shown in FIG. 2 has asubstantially octagonal circumference. The bone repair tray 20 includesa well region 24 that can hold fluid such as blood that can be used tomoisten the bone repair composition 10 before use. The tray shown inFIG. 2 also includes two grip regions 26 that are positioned on eitherside of the bone repair composition 10 to facilitate gripping andwithdrawing the bone repair composition 10 from the tray 20. The tray 20can also include a support region 28 positioned in the middle of thewell region 24 and between the grip regions 26 that supports the bonerepair composition 10 above the bottom of the tray, which allows greaterfluid access and easier withdrawal of the bone repair composition 10.The support region 28 can be configured to correspond to the shape ofthe bone repair composition 10, but slightly smaller so that the bonerepair composition 10 will overhand the support region when placed inthe tray 20. For example, when a rectangular bone repair composition 10is used, the support region 28 will also be a rectangle havingproportional dimensions, but slightly smaller. The tray 20 also includea tray wall 30 that extends from the tray sealing region 22 to the wellregion, thereby connecting the upper and lower portions of the tray 20.

The package used for the kit can also include a bone repair kit cover 40that can be used to hold and protect the bone repair tray 20. FIGS.3A-3D provide drawings showing an embodiment of the bone repair kitcover 40 having a substantially octagonal circumference that can be usedto hold the bone repair tray 20 shown in FIG. 2. The bone repair kit 40includes a flat cover sealing region 42 that runs around thecircumference of the bone repair kit cover 40 that provides a surfacethat can be associated with or bonded to a flat sheet (e.g., a papersheet, not shown) to seal the bone repair kit cover 40 with the bonerepair tray 20 being sealed within. A cover wall 46 is perpendicular tothe flat cover sealing region 42 and extends to a cover region 44,thereby forming a closed, dish shape with dimensions sufficient to allowthe bone repair kit cover 40 to enclose the bone repair tray 20.

The kits of the invention may also comprise, or be packaged with, aninstrument for assisting with the placement of the bone repaircomposition onto or within the body of an animal, for example, a mammal.Such an instrument may be a syringe, pipette, forceps, or any suchmedically approved delivery vehicle.

The present invention is illustrated by the following examples. It is tobe understood that the particular examples, materials, amounts, andprocedures are to be interpreted broadly in accordance with the scopeand spirit of the invention as set forth herein.

Examples Example 1: Process for Preparing Bone Repair Material

A production flow diagram showing the main steps in the production ofcollagen bone composite strips is provided by FIG. 4. To summarize, theprocess for preparing the bone repair composition includes the steps ofadding collagen to acid; adding glycosaminoglycan to the collagen toform the GaG-collagen co-precipitate; adding tri-calcium phosphate andthe bioactive glass to the collagen mixture; adding the mixture to amold having the desired shape of the bone repair composition,freeze-drying the bone repair composition to remove water, cross-linkingthe composition, packaging the bone repair composition into a kit, andsterilizing the packaged bone repair composition.

Dispersion Process

During the dispersion process the desired outcome is two dispersions, a0.85% collagen only (or “Neat) component and a 0.82% collagen dispersionco-precipitated with 0.023% glycosaminoglycan (GAG) (0.2415 gm/1070 ml).Following the flow diagram shown in FIG. 5, lots were made using thesame raw materials and scaled to appropriate amounts. All material wasreceived with a certificate of analysis (CofA) meeting the requirementsof USP or “Certified for Human Use”. Materials were measured out using aclean graduated cylinder (for liquids) and an OHAUS 4 place balance forsolids. The initial collagen dispersion, containing 0.85% collagen, wasmade by mixing collagen, lactic acid, and ultrapure water in a largeclean beaker. The material was hand stirred with a glass stir rod andallowed to rest in refrigerator (˜4° C.) for 12-24 hours. Once “wetting”period is complete the mixture is dispersed using a Waring Blender at aspeed of 3-5 k RPM for 3 minutes. The 0.85% dispersed collagen wasdivided out to 57% “Neat” and 43% used to make a collagen-co-GAGdispersion. The 0.345% GAG dispersion was created by dispersing GAG,lactic acid, and ultrapure water in a clean beaker.

Lyophilization

Once the collagen dispersion has been prepared, approximately 18.2 gm ofthe dispersion is poured into a 104.75 mm×21.78 mm×5.00 mm well of ahard coat anodized aluminum plate. Once all wells are full, each plateis placed in a −80° C. freezer for greater than 1 hour or untilcompletely frozen. After the material is frozen each plate is moved intoa pre-frozen lyophilizer (e.g., a Virtis™ lyophilizer). A 24-hour cycleis used to remove any water from the dispersion to leave a highly porouscollagen/GAG/bioceramic strip

Cross-Linking

After the completion of lyophilization, the samples are removed from themold using clean forceps and placed into a formaldehyde cross-linkingchamber. An airstone placed in 10% formaldehyde solution is used tocreate a formaldehyde vaper into the chamber. This process is preferablyrun for about 1 to 2 hours. At the completion of this cycle, an airstoneis activated in fresh water to provide humid air to outgas the samples,preferably for about 1 to 2 hours. Outgassing can be carried out usingnitrogen flood or standard atmosphere with a relative humidity of 30 to60%.

Packaging

Packaging consists of an inner and an outer thermoformed tray (FIGS. 2 &3) with a sealed and labeled Tyvek lid on each tray. At the completionof outgassing, each sample is placed in an inner thermoformed tray. Eachtray sealed with a breathable Tyvek lid using a 4-post pneumatic heatsealer. Before and after sealing of product occurred three samples weretested and passed for visual seal integrity. The inner trays were thenlabeled with labels.

Sterilization

The bone repair material should be sterilized before use. Preferably thebone repair material is sterilized using gamma irradiation. Gamma raysare a form of electromagnetic radiation, similar to x-rays but with ahigher energy. Gamma rays can be obtained from radionuclide elementssuch as cobalt 60, which emit gamma rays during radioactive decay. Gammarays can readily pass through the packaging of the kit and kill bacteriathat may be present in the bone repair material by breaking the covalentbonds present in bacterial DNA. For sterilization of the bone repairmaterial, preferably 25 to 40 kiloGrays of gamma irradiation are appliedto the bone repair material within the plastic packaging of the kit.

The complete disclosure of all patents, patent applications, andpublications, and electronically available materials cited herein areincorporated by reference. Any disagreement between materialincorporated by reference and the specification is resolved in favor ofthe specification. The foregoing detailed description and examples havebeen given for clarity of understanding only. No unnecessary limitationsare to be understood therefrom. The invention is not limited to theexact details shown and described, for variations obvious to one skilledin the art will be included within the invention defined by the claims.

1-25. (canceled)
 26. A bone repair composition, comprising a particulatedispersion comprising a collagen component, a bone growth stimulator,and a bioactive glass, wherein the bioactive glass ranges from 15% to25% by weight of the particulate dispersion and comprises bioactiveglass particles having a size from 250 to 2000 microns, the bone growthstimulator ranges from 75% to 85% by weight of the particulatedispersion and comprises bone growth stimulator particles having a sizefrom 250 to 2500 microns, and the collagen component ranges from 0.5% to5% by weight of the particulate dispersion.
 27. The composition of claim26, wherein the bone growth stimulator particles have a size from 400 to1600 microns.
 28. The composition of claim 26, wherein the bioactiveglass particles have a size from 250 to 1500 microns.
 29. Thecomposition of claim 26, wherein the bioactive glass develops ahydroxyapatite surface layer upon implantation within a subject.
 30. Thecomposition of claim 26, wherein the particulate dispersion isconfigured as a rectangular strip.
 31. The composition of claim 26,wherein the collagen component and is blended into an aqueous dispersionbefore incorporation into the particulate dispersion.
 32. Thecomposition of claim 31, wherein the particulate dispersion comprises across-linked dispersion formed from the aqueous dispersion of thecollagen compound.
 33. The composition of claim 32, wherein thecross-linked dispersion is formed from the aqueous dispersion mixed withthe bioactive glass and the bone growth stimulator, freeze-dried, andthen cross-linked.
 34. The composition of claim 26, wherein the collagencompound comprises a type I collagen.
 35. The composition of claim 34,wherein the collagen compound further comprises a type Icollagen-glycosaminoglycan coprecipitate.
 36. A method of repairing abone defect, comprising administering a composition according to claim26 to the site of the bone defect.
 37. The method of claim 36, whereinthe composition is hydrated before administering the bone repaircomposition to the site of the bone defect.
 38. The method of claim 36,wherein the bone repair composition is hydrated with autologous blood.39. The method of claim 36, wherein the bone defect is, or is theresult, a simple fracture, a compound fracture, external fixation,internal fixation, joint reconstruction, arthroplasty, degenerative discdisease, avascular osteonecrosis, osteosarcoma fracture, fracturenon-unions, spinal fusion, disc augmentation, or bone regeneration inorthopedic implants.
 40. A bone repair kit, comprising: a solidparticulate dispersion of a collagen component, a bone growthstimulator, and a bioactive glass, wherein the solid particulatedispersion comprises a sterilized collagen cross-linked dispersion; anda package packaging for holding the bone repair composition.
 41. Thebone repair kit of claim 40, wherein the bone repair composition isconfigured as a rectangular strip.
 42. The bone repair kit of claim 40,wherein the packaging includes a tray configured to fit the shape of thebone repair composition.
 43. The bone repair kit of claim 42, whereinthe tray includes one or more grip regions to facilitate access to thebone repair composition.
 44. The bone repair kit of claim 42, whereinthe tray includes a support region that holds the bone repaircomposition above the bottom of the tray.
 45. The bone repair kit ofclaim 40, wherein the kit includes a cover that can be sealed with asheet to hold the tray.
 46. The bone repair kit of claim 40, wherein thepackage comprises high density polyethylene.